The ClimateMaster Trilogy® 40 Q-Mode™ Geothermal Heat Pump is the outcome of a 5 year collaboration between ClimateMaster, Inc., and Oak Ridge National Laboratory (ORNL). The Trilogy 40 Q-Mode is an ultra- high-efficiency geothermal heat pump that provides space heating, cooling, and water heating. Laboratory evaluation and modeling by ORNL predicted that the Trilogy 40 Q-Mode could save 55% to 61% of annual energy use and cost for space conditioning and water heating in residential applications versus new mini- mum efficiency (SEER 13) air-source heat pumps and electric resistance storage water heaters. These sav- ings results were confirmed in field trials. The Trilogy series also became the first geothermal heat pumps ever certified by the Air Conditioning, Heating, and Refrigeration Institute (AHRI) to exceed 40 EER at ground-loop (GLHP) conditions.